Scavenging air pump or compressor



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O.E.JORGENSEN SCAVENGING AIR PUMP OR COMPRESSOR Filed Dec. 5. 1924 Patented Mar. 1, 1927.

oit-.Liv asimiaoaennfsn'n, or sonneri" Hints, new Yoran,

ASSEGNORy TO WORTH'ING-TON VIRGENEA.

SCAVENGING AIR IEM'Y @dit COYIVIRSSOR'.

Application filed December 3, 19534.

This invention relates to an ai-r pump or compressor designed especially for use as a scavenging pump for internal combustion engi. les, but applicable also to other uses.

The' 'especial- Object of the invention is to provide a. simple, compact and durable cou:- struction of large capacity, by which the quantity of scaifenging. air required for large marine Diesel or other oil-burning engines may be secured withr certainty and accurate timing, while the parts are' such as to be readily machined for the required' accuracy, and which wil-l permit ready and: quick access to all the parts for purposes of, adjustment and repair.

For a full understanding of the invention, a detailed description of'a scavenging air pump embodyingY all the features ofthe invention. in their preferred form wi-ll`now be given in connection with the accompanying drawings forming a part of this specification, and the Yfeatures formi-ngl the invention then. specifically pointed out in the claims.

In the drawings- Figure L isa: vertical: section: of the scavenging pump and its drive with the pistons at the end of their upward stroke;

.Figures 2 ancL 3 are similar partial sections showing, respectively, the pump on half downward stroke and at the end of its downward stroke; and

Figure i is a partial elevation of one side of the pump, showin@ the valve linkage.

rilhe scavenging pump shown is of the general type and embodies many of the features of the scavenging pump shown in lmy United StatesLetters Patent No. 1,447,514, dated March 6, 1923, and is used for the same purpose, so that no detailed description of the arrangement of the pump relatively to the engine or its operation in connection with the latter need be given, reference being made to said Letters Patent for such matter.

Referring to the drawings, A, A are upper and lower cylinders separated by septum a; B, B the upper and lower pistons moving in these cylinders and driven by common piston rod C shown as actuated by cross-head D, crank rod E and crank F from shaft G which is geared to the crank shaft H, being shown as driven by gears 10, ll. The scavenging pump shown is designed for a four cylinder engine, the gearing 10, l1 therefor being geared to drive the pump olution of the crank shaft.

sensu. No. 753,592.

pistons two revolutions to one of the crank shaft, so as to obtain separate delivery of scavenging` air to each cylinder on? one rev- It will be understood, however, that this timing will depend uponl the number of cylinders used and the number of pump air deliveries required for each revolution of the crank shaft.

The air inlet chamber extend-s about the cylinderto connect.' with' inlet 'passa-ges K, K', forrthe respective cylinders, tlie inlet passage K for the lower cyl-i'nd-er Communicating with passages 7b, Z communci'ati-ng, re-

spectively, with the upper and lower ends of cylinder A through valve chamber m, and

the upper'inlet chamber K communicating through passages c, with, respectively, the lower and upper ends Aof cylinderv A through valve chamber fm. lithin the valve chambers m, lmf,grespectively, and controlling tlie inlet and discharge for the' lower and' upper cylinders A, A', are rotary valves r, 1" formed with a pair ofl d'iametricaliyopl site seo'm'ents l which successivelV o enV` and close ports 2' connecting the valve' cli'a'mbers fm, m with the opposite ends of the cylinders and with the lpump discharge chamber L. These rotary valves are timed to make. one revolution to two revolutions of the pistons B, B and are shown as driven by belt or chain l2 from a cam shaft M or other suitably timed shaft of the engine, the valves being connected by bell-cranks 13 and links 14- so as to move together and be driven by a single connection to their driving shaft.

The operation of the` pump will be understood from a brief description in connection with the position Figur-es l to 3. In Fig. l, the pistonsare on dead center at the'ends of their upward stroke, the valve segments l ot both valves, r are closing the inlet and discharge ports 2 for both cylinders; in Fig. 2 the pistons are in the middle of their downward stroke and the valves 7, r have been rotated to the left from the position of Fig. l so as to move the'valve segments l into position to connect inlet passage K .with passage Z for suction above the piston B and the lower end of cylinder A with the discharge L' through passage K and valve chamber m, the valve 7" having been moved simultaneously so that cylinder A is receiving air from inlet K through passage Z above the piston and discharging below the piston through passage 7c and valve chamber fm, simultaneous discharge from both of the double-acting cylinders A, A being thus secured. A large. quantity of air is thus delivered under the required pressure with a small, compact construction.

In F ig. 3 the pistons have completed their downward stroke and the valves r, r have been moved a quarter revolution to again close the ports 2 for both cylinders, the operation described above in connection with Fig. 2 being repeated on the upward stroke of the pistons as the valves continue their rotation, but with the connections reversed so that th-e lower' ends of the cylinders are receiving air and the upper ends of the cylinders delivering air through the valves r, r.

It will be understood that the broader features of the invention include a construction employing only a single. double-acting piston, but preferably a plurality of doubleacting pistons driven together are used, for obtaining the desired capacity with a smaller pump, and such a construction is specifically claimed.

vWhat I claim is:

l. A double-acting air pump or compressor having a common discharge chamber at one side of the cylinder, combined inlet and discharge passages at each end oi the cylinder adjacent the discharge chamber, a common suction chamber for both ends of the cylinder ext-ending about the cylinder from the suction connection, a common valve chamber between the inlet chamber and discharge chamber and connecting directly with said chambers and with the inlet and discharge passages, and a rotary valve having segments that alternately connect th-e respective ends of the cylinder with the inlet and discharge chambers for inlet and discharge at the opposite ends of the cylinder.

2. A double-acting air pump or compressor having two cylinders arranged in line, a double-acting piston in each cylinder, means for driving said pistons to make their discharge strokes simultaneously, ga common discharge for said cylinders, a rotary valve for each cylinder, and means for actuating said rotary valves to control the inlet and discharge for the respective cylinders to secure a simultaneous inlet and discharge at the corresponding ends ot' the two cylinders.

3. In a multiple cylinder internal combustion engine, an air pump consisting or" a plurality of double-acting cylinders arranged in line, pistons in said cylinders, a common discharge for said cylinders, a rotary valve for each cylinder controlling the inlet and discharge of said cylinder, and means for actuating the pistons and valves from the engine to secure a simultaneous discharge from said cylinders, said actuating means being timed to produce such asimultaneous discharge for the scavenging operation of each cylinder.

In testimony whereof, I have hereunto set my hand.

OLAV ESKIL JORGENSEN. 

